The current invention relates long handled sports equipment, such as softball or baseball bats, for striking balls. More particularly, the current invention pertains to designs for bats that yield a particular cross-sectional shape to improve the hitting characteristics thereof.
It can be appreciated that numerous attempts have been made to improve the performance of a bat. These prior attempts have included the addition of various shells, inserts, materials, and shapes of the bat in order to improve its performance or usage. For example, U.S. Pat. Nos. 6,761,653, 6,733,404, 6,497,631, 6,425,836, 6,176,795, 6,022,282, 4,930,772, 4,331,330, and 3,990,699, U.S. Patent Application Publication No. 2002/0016230, and Japanese Patent No. JP5023407 disclose various attempts to improve the performance or use of a bat.
The performance of a bat is generally based upon the weight of the bat, length of the bat, and the impact response of the bat at and during impact with a ball. The weight and length characteristics of bats have practical, as well as batter preference, limitations. As such, most prior art attempts to improve bat technology have been focused on the impact response of the bat at and during impact with a ball.
For example, studies have been made to measure the coefficient of restitution (COR) between a ball and a bat. The research has shown that the COR was dependent on both the flexural stiffness, with reference to the axis of a bat, and the circumferential stiffness, or elasticity, of the bat. The research found that the COR rose with increasing bending stiffness and decreasing circumferential stiffness.
Other research has shown that the elasticity of the bat is a greater factor in determining the COR of the bat. For example, research has shown that when the contact time between the ball and the bat match the time required for the bat to deflect and return to its original position, the COR increases because some of the vibrational energy in the bat was returned to the ball. This has been referred to an isoharmonic impact.
It is known that as the weight of a bat is reduced, the batter can swing the bat with additional speed thereby parting more force on the ball during impact. Bat performance therefore varies with the individual player's swing speed. Additionally, other research has shown that the performance factors of a bat can be increased when the bending momentum in the bat is increased.
It is theorized that the speed of the bat, and more particularly the speed of the hitting area of the bat, through the hitting zone can be affected by the relative flexibility between the handle and the barrel, or flexibility in the attachment between the handle and barrel depending on the overall swing speed of the bat. An important location for the actual measurement of overall bat swing speed is in the hitting zone—roughly defined by the strike zone for each individual batter. In essence, it is theorized that handle flexibility and can affect the relative speed of the barrel through the hitting zone even if the overall speed of the bat is substantially consistent. For example, it is theorized that a player with high swing speed can get a better performance with a stiff handle bat, where as a player with lower swing speed will perform better with a flexible handle bat provided all the parameters remains the same. For example, a professional player should perform better with a stiff handle bat compared to a high school player, who should perform better with a flexible handle bat
What is needed is an improved bat that provides increased performance. This improved bat preferably has a design that alters flexibility characteristics such that it has an improved batted ball performance. This needed bat is lacking in the art.